Jack plugs



S. T. DEAKIN July 29, 1969 JACK PLUGS Filed March 7, 1967 STANLEY THOMAS By JOHN P. CHANDLE His At'c DEAKIN ventor or-ney United States Patent US. Cl. 339-17 Claims ABSTRACT OF THE DISCLOSURE A jack plug has two contacts for electrically connecting and mechanically fixing the jack plug to a selector board, one contact being capable of passing through a hole in the board from one side of the board to make electrical connection with a conductive portion located on the other side of the board, and the other contact being capable of making electrical connection with a conductive portion on the said one side of the board, the said other contact being electrically independent of said one contact and the contacts being operable to grip between them the board in electrical connection respectively with the conductive portions on opposite sides thereof.

The invention relates to jack plugs capable of being used on selector boards of the kind comprising a sheet like body of insulating material having at least one conductive portion on each side of the said body and at least one hole extending through the body from one side to the other, which hole preferably passes through the conductive portion on at least one of the sides.

According to the invention a jack plug capable of being used with a selector board of the kind described is provided with two contacts for electrically connecting and mechanically fixing the jack plug to the board, one contact being capable of passing from one side of the board through the aforesaid hole to make electrical connection with the conductive portion which is located on the other side of the board, and the other contact being capable of making electrical connection with the conductive portion of the said one side of the board, the said other contact being electrically independent of said one contact and the contacts being operable to grip between them the board in electrical connection respectively, with the conductive portion on opposite sides thereof.

In the case where the plug is to be employed with a board in which the hole passes through the conductive portion on one of the sides of the board, one contact may be arranged to seat on said conductive portion and the other contact be laterally displaced from the first contact to engage the conductive portion on the other side of the board.

The contacts may be spring urged into gripping engagement with the board. Thus the said other contact may be capable of being spring urged into engagement with its associated conductive portion.

In one form of the invention the said one contact has a laterally extending projection engageable with the conductive portion on the other side of the board after the contact has been passed through the board but of such a size that it does not prevent the contact being passed through the hole and the said other contact is capable of being spring urged into engagement with its associated conductive portion, whereby, in use, the said spring or spring effect tends to urge the projection of the said one contact into engagement with its associated conductive portion.

Preferably the said size of the one contact which allows the contact to pass through the hole is in a direction which lies at an angle to the axis of the hole and the arrangement is such that the plug must be rotated against the spring or spring effect before the contact can be withdrawn.

The plug may house a diode connected to the two contacts of the plug.

The plug may also be provided with an additional fixing member, which member is, in construction, a duplicate of the said one contact and which member is capable of passing through a further hole in the board to provide a three point engagement between the plug and the board.

The invention also includes the combination of a jack plug as above described with a selector board of the above type in which both sides of the board have a plurality of strip-like conductive portions, each portion being spaced from and extending parallel to its adjacent portions and the portions on one side of the board being at an angle (e.g., at right angles) to the portions on the other side of the board, and in which the board has a first set of holes, each hole extending between the two sides of the board and passing through a part of one of the conductive portions on the other side of the board which is not directly opposed to a part of one of the conductive portions on the said one side of the board, with the one contact of the plug passing through one of the holes in the board and engaging with one of the conductive portions through which the hole passes on the other side of the board and with the other contact of the jack plug engaging one of the conductive portions on the said one side of the board.

The board may also be provided with a second set of holes, the first set of holes passing through the conductive portions on the one side of the board and the second set of holes passing through the conductive portions on the other side of the board.

By way of example, a specific embodiment in accordance with the invention will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a fragmentary plan view of a selector board having a jack plug attached thereto,

FIGURE 2 is a plan view of the jack plug shown in FIGURE 1,

FIGURE 3 is a sectional elevation of the jack plug along line 33 in FIGURE 1,

FIGURE 4 is a perspective view of the said one contact of the jack plug,

FIGURE 5 is a perspective view of the said other contact of the jack plug, and

FIGURE 6 is a diagrammatic view, being a section on the line 66 in FIGURE 1.

With reference to the drawings, a selector board comprises a square or rectangular sheet 10 of insulating material having on one side a plurality of spaced apart, parallel strips 11 of conductive material extending between one pair of opposed sides of the sheet and having on the other side a further plurality of spaced apart parallel strips 12 of electrically conductive material extending between the other pair of opposed sides. The strips 11, 12 are also arranged so that the strips 11 are at right angles to the strips -12. The combination of the strips 11, 12 thus forms the lattice shown in FIGURE 1. One method of manufacturing the board is to coat each surface of a sheet of insulating material with the electrically conductive material and then to remove the unwanted portions by milling or etching.

The board 10 is also provided with two sets of symmetrically located holes 13, 14. Each hole is such that it passes through only one of the conductive strips 11, 12 on only one side of the sheet 10, the holes 13 passing through the strips 11 and the holes 14 passing through the strips 12.

For use with the board constructed as described above, jack plugs 15 are provided, each plug housing a diode 16 within a moulding 17 of insulating material. Each plug is provided with two contacts 20, 21 which are connected to the leads 18, 19 respectively of the diode and, which, when the plug is attached to the board, connect one of the strips 11 to one of the strips 12, the diode thereby being readily inserted into an electric circuit containing a selected pair of strips 11, 12.

The contact 20 (see especially FIGURE 4) comprises a downwardly depending bar having a top portion 22 for connection to the lead 18 of the diode and a step 23 adjacent its bottom end 25 for engagement with one of the strips 12. The contact 20 is also provided with another step 24 for limiting the longitudinal movementof the bar into the moulding 17 of the jack plug. The dimensions of the bottom end 25 of the contact 20 are such that it may be passed through one of the holes 14, the plug being held at an acute angle to the top surface of the board, and then moved laterally of the hole, by straightening the plug into a vertical position, so that the step 23 will engage the selected strip 12. This arrangement can be seen especially from FIGURE 6 where the distance between the chained line 40 and the edge 41 can be seen to be less than the width of the hole 14 in the board. By rotating the plug so that the edge 41 is vertical the plug can be inserted into or removed from the hole.

The other contact 21, see especially FIGURE 5, is made from a length of wire bent to form an upturned U, the base 28 of the U being connected to the lead 19 of the diode and the free ends 26 of the legs 27 of the U being for engagement with the selected strip 11 and being bent so that, when the step 23 of the contact 20 is in engagement with the strip 12, the ends 26 will be spring urged into engagement with the strip 11. The fact that the ends 26 are spring urged into engagement with the strip 11 also acts to hold the step 23 of the contact 20 into engagement with the selected strip 12. The moulding 17 is also provided with a portion 29 having grooves for the legs 27 of the contact 21 and the lead 19 of the diode.

The jack plug is also provided with an additional fixing member 30 which is of identical construction to the contact 20 but which is provided only as additional means for fixing the jack plug to the board. For this reason the member is insulated, by means of the moulding 17, from the contacts 20, 21 and the diode leads 18, 19. In use, the bottom end of the member 30 is passed through one of the holes 13 at the same time as the bottom end of the contact 20 i passed through one of the holes 14. As has been described the contact 20 and member 30 are arranged so that the plug may be removed from the board by tipping the plug to compress the free ends of the legs 27 of the contact 21 and thereby allow the bottom ends of the contact 20 and the member 30 to be passed through their holes 14, 13.

It will be appreciated that a plurality of jack plugs may be fixed to the board for connecting different pairs of strips 11, 12 of electrically conductive material. Another such plug is shown in chain lines in FIGURE 1. The three point contact of the jack plug to the board also provides a stable fixing therefor.

I claim:

1. In combination a selector board comprising a sheetlike body of insulating material, a plurality of strip-like conductive portions on each side of the said body, each portion being spaced from and extending parallel to its adjacent portions and the portions on one side of the body being at an angle to the portions on the other side of the body and a first set of holes, each hole extending between the two sides of the body and passing through a part of one of the conductive portions on the other side of the body which is not directly opposed to a part of one of the conductive portions on the said one side of the body, and an electrical plug provided with two separate contacts for electrically connecting and mechanically fixing the plug to the board, one contact passing from one side of the insulating body of the board through one of the said holes therein and making electrical connection with the conductive portion on the other side of the body through which the said hole passes, and the other contact making electrical connection with one of the conductive portions on the said one side of the body.

2. The combination as claimed in claim 1 in which the board has a second set of holes, the second set of holes passing through only the conductive portions on the said one side of the body of the board and the aforesaid first set of holes passing through only the conductive portions on the other side of the body.

3. The combination as claimed in claim 2 which the plug has an additional fixing member which member passes through one ofthe holes of the said second set of holes, whereby there is provided a three-position engagement between the plug and the board.

4. For use with a selector board comprising a sheet-like body of insulating board, at least one conductive portion on each side of the said body and at least one first hole extending through the body from one side to the other, an electrical plug provided with two separate contacts for electrically connecting the conductive portions on each side of the insulating body of the board and for mechanically fixing the plug to the board, one contact being capable of passing from one side of the body through the said hole in the body and making electrical connection with the conductive portion on the other side of the body and the other contact being capable of making electrical connection with the conductive portion on the said one side of the body, and an additional fixing member which member is capable of passing through a second hole in the insulating body of the board to provide a three-position engagement between the plug and the board.

5. An electrical plug as claimed in claim 4 in which the said one contact has a laterally extending projection engageable with the conductive portion on the other side of the insulating body of the board after the said one contact has been passed through the said first hole in the body but the projection is of such a size that it does not prevent the said one contact being passed through the hole and the said other contact is capable of being urged by spring means into engagement with its associated conductive portion, the said spring means tending to urge the projection of the said one contact into engagement with its associated conductive portion.

References Cited UNITED STATES PATENTS 2,969,519 1/ 1961 Thomas. 3,045,077 7/ 1962 Knanishu. 3,209,209 9/1965 Mueller.

MARVIN A. CHAMPION, Primary Examiner P. A. CLIFFORD, Assistant Examiner US. Cl. X.R. 39-18 

